1. Technical Field
The present invention relates to receipt printer that produces printout requiring counterfeiting prevention, to a method of controlling the receipt printer, and to a program for the same.
2. Related Art
Counterfeit receipts have become an increasingly common problem due to the effects of the global economy. Counterfeit receipts may be used to take products out of a store, or to return products to a store and receive money in return.
There are also counterfeiters that produce and sell counterfeit receipts to customers. Such counterfeiters purchase the same model of receipt printer used by a retailer to produce the counterfeit receipts. In extreme cases, the counterfeiter may even steal the receipt printer from the retailer in order to produce counterfeit receipts.
A printer that is used to produce printout requiring protection against counterfeiting is taught in Japanese Unexamined Patent Appl. Pub. JP-A-2002-326443, for example. The printer taught in JP-A-2002-326443 can produce printout that is difficult to counterfeit and yet enables easily identifying counterfeit items by printing plural items of information in visible ink as well as specialty inks such as fluorescent ink and infrared absorbing ink.
A problem with the receipt printer taught in JP-A-2002-326443, however, is that while it can effectively suppress counterfeit receipts when applied to a receipt printer used for issuing receipts, acquiring possession of the receipt printer makes counterfeiting possible. Making the production of counterfeit receipts difficult even when in possession of the receipt printer is therefore desirable. This can conceivably also eliminate receipt counterfeiters, and thereby effectively prevent counterfeit receipts.